I bet you didn't know that this thread would have a part 2

Automaticity is the ability to do everyday things without thinking or with very little conscious consideration of the action. Things like reading, speaking or making the bed can be acomplished with a high degree of automaticity, and most of us complete many tasks without any real conscious thought about what we're doing as these skills are embedded in habit and repetition. Muscle memory requires a great deal of automacity but things like the visual recognition required to read fluently is dependent on the automaticity that comes with learning and practice and repetition as the skills required are consolidated into the background memory processes and frees up the foreground working memory for more focussed tasks and activities.

The higher the cognitive burden, the longer it takes to gain a degree of automaticity. Learning the alphabet or numbers requires a great deal of cognitive input until recognition is completely embedded in memory, and lesser or no conscious input is needed to form words out of letters etc. Things that carry a low cognitive burden like flushing the loo are more easily filed away as something that can be done without thinking through or having to consciously remember. For most, anyway.

Conflicting input can disrupt even long established automaticity, and this was observed in the 1930's when John Ridley Stroop confused people by printing the names of the colors in other colors, and measured how long it took to process the incongruity. When you're cycling along and suddenly hit a small unforseen bump, your procedural memory hiccups for the moment it takes your attention to focus sharply on what's happening, process the interruption, and for normal service to resume.

Research shows that we indulge in behavioural automaticity to soothe ourselves, and take satisfaction and comfort in familiar routines and habits and it plays a part in some obsessive compulsive self-soothing behaviours. Autisic people particularly find ease in familiarity but achieving automaticity is often more difficult as greater sensitivity to stimulation disrupts the formation of ingrained memories needed to be able to take the automatic, sucessful completion of a task for granted. This is why some simple tasks can sometimes be very frustrating, and repetition of others that have been mastered so soothing to those affected.